1. Field of the Invention
This invention relates generally to image recognition techniques using a signal from an imaging apparatus such as a TV camera, and particularly to a moving body recognition circuit using luminance signal and moving body tracking apparatus using the moving body recognition circuit.
2. Prior Art
Heretofore, an imaging apparatus such as a TV camera has been applied to visual applications and monitoring applications in medical fields and robots of industrial field. In these applications, images are merely reproduced and recognized. Recently, in factory automations, robots, and remote monitorings, it is required that a particular moving body be monitored and tracked by controlling the movement of an imaging apparatus. However, in conventional moving body monitoring and tracking apparatus, separation between a moving body and a background cannot automatically be correctly be performed. In addition, tracking of desired moving body is not satisfactorily performed in a conventional system in which a camera is continuously panned and tilted in accordance with the movement of the moving body. This is because even a background imaged with small movements of the camera stand is recognized as moving bodies in the image, and because even small movements in a background are also recognized as moving bodies. More specificially, in the case of an image of a landscape, the movement of leaves by a light wind is also recognized by the tracking apparatus as a moving body. Electric signals caused by such leaf movements are not required, and the signal operates as noise signals in the tracking apparatus. Besides, if there are moving bodies in a particular landscape, one moving body cannot be tracked. More specifically, during tracking of a person moving at a slow speed, if an automobile moving at a speed quicker than the person crosses in such landscape image, the target which is to be tracked is changed from the person to the automobile. Therefore, the person cannot be tracked by using such conventional tracking apparatus.